Problem: Add. ${9} + 6 =$
Solution: First, let's jump ${9}$ on the number line. $+9$ $0$ $5$ $10$ $15$ $20$ Next, let's jump $6$ on the number line. $+9$ $+6$ $0$ $5$ $10$ $15$ $20$ The jumps end at the number ${15}$. $+9$ $+6$ $\boxed{15}$ $0$ $5$ $10$ $20$ ${9} + 6 = {15}$